01 - In a medium bowl or jar, combine the oats, milk, Greek yogurt, brown sugar, cinnamon, and vanilla extract. Stir well until fully incorporated and smooth.
02 - Cover the container tightly and refrigerate for at least 8 hours or overnight to allow oats to soften and absorb the liquid.
03 - In the morning, stir the oats thoroughly. If the mixture is too thick, add a splash of milk to reach desired consistency.
04 - Top with banana slices, chopped nuts, and fresh berries if using. Serve chilled.